von pittler



Patented January 19, 1904.

UNITED STATES PATENT. OFFICE.

WILHELM VON PITTLER, OF LEIPZIG-GOHLIS, GERMANY.

I ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 750,219, dated January19, 1904.

Application filed April 23, 1902. Serial No- 104,255. (No model.)

To all whom it may concern.-

Be it known that I, WILHELM VON PITTLER, a subject of the GermanEmperor, residing at Leipzig-Goblis, Germany, have invented certain newand useful Improvements in Rotary Engines, of which the following is aspecification, reference being had to the accompanying drawings, forminga part hereof.

This invention is concerned with improvements in rotary motors, pumps,and like machines wherein a rotating head is employed to carry one ormore reciprocating pistons. These reciprocating pistons in machines ofthis character are generally in the nature of sliding plates, one end ofthe same being made to follow a guiding-surface, usually the surface ofthe shell or casing of the machine, said surface having a curvature moreor less complex, and thereby causing the sliding plates or piston-slidesto reciprocate back and forth in corresponding slots in the rotatinghead according to the variations of curvature of the guiding surfaceagainst which they bear. Against these piston-slides when theapparatusis used as a motor the impelling fluid'as, for example, Water,steam, compressed air, explosive gases, &c. -presses and causes the'head to revolve.

In accordance with the present invention the piston-slides intherevolving head are.

made to reciprocate longitudinally with respect to the rotating head asdistinguished thereby securing a uniform space between the rotating headand the flat portion of the curved surfaces and providing a free andunobstructed passage for the steam or other fluid which operates or isoperated upon by the apparatus.

In the drawings, Figure 1 is aview, partly in longitudinal section, of amachine embodying the improvements and having a single curved'or camsurface at one end or head of the power or operating chamber.

of the machine shown in Fig. 1. Fig. 3 is a detail view, partly insection, showing the ro:- tating head partly removed from the power Fig.4: is a plan view the line 7 7 of the machine shown in Fig. 6.

Fig. 8 is a detail sectional view of the power or operating chamber withthe rotating head removed. Fig. 9 represents a development Fig. 2 is asection on the plane indicated by the line 2 2 of both cams shown inFig. 6 and shows graphically the positions of the slides at one point inthe rotation of the head; Fig.10 represents in a development a modifiedform of the cams. similar to Figs. 2 and 7 and shows the samemodifiedform as Fig. 10.

The shell or casing, which for convenience in construction and in theassembling of parts may comprise two portions a and (4 adapted to besecured together in any well-known manner, is mounted on a suitable base6. A

shaft 0 havin an enlarged art 0, rotates in bearings d and sleeves e and0 Rigidly secured to the enlarged part c of this shaft isa Fig. 11represents a section view rotating head f, andin Figs. 1 to 3,inclusive,

this rotating head is provided with two slots f and f one hundred andeighty degrees apart, in which are fitted two slides g and g adapted tomove back and forth in said slots longitudinally with respect to therotating head and having a working fit between the sleeve 6 and the wallof the chamber a. At one end of the power or operating chamber a is anannular cam c', which may be formed onor rigidly secured to the portiona of the shell and of which the portion a: is aflat surface, While therise forms a curved surface,

which ascends gradually in the present case over about one quarter ofthe circular surface of the cam to a maximum 3/ and then falls graduallyover the next quarter of the surface, the rise and fall of the curvaturebeing symmetrical with respect to the maximum against the curvedsurfaces of the cams, lonrise although the precise extent of the riseand fall portions of the surface may obviously be varied. The ends ofthe slides g and are flat, and as the head f revolves the ends of theseslides next the cam v. are always 1n working contact with its surface,being held thereto by springs j.

Although it is essential in machines of this character that thepiston-slides shall always remain close to their limiting or guidingsurface, (here the surface of the cam v',) yet they should not be heldagainst same so tightly as to cause undue frictlon. Accordingly thesleeves and a are provided, the former being screw-threaded at Z', and anut is provided on the end of the portion a of the casing and bearsagainst the sleeve whereby the position of the rotating head f may bereadily adjusted from time to time to take up wear. Furthermore, achannel f is provided in the rotating head at one side of each slide totransmit the pressure of the motive fluid to the rear or inner end ofthe slide, so thata light spring may be used to keep the slide alwaysagainst its guiding-surface.

In Figs. 6 to 9, inclusive, is shown a machine having an annular cam 1"4' at each end of the chamber a, the rotating head f being provided withfour piston-slides 7', g g", and cfi, which are ninety degrees apart.The slides which are oppositely arranged, or one hundred and eightydegrees apart, are in working contact with the cam on one side, whilethe other two slides are in working contact with the second cam, so thatas the head revolves the alternate slides are guided by the same cam. Inorder to equalize the pressure on both ends of the slides, openings fare provided in the rotating head. The same means for adjusting theposition of the rotating head are provided as are shown and describedwith respect to Figs. 1, 2, and 3. Additional means, however, areprovided in a nut 7/1, threaded in the end of the portion a" of thecasing for adjusting the cam 1 which may be formed integral with asleeve 12 with respect to the cam the latter being rigidly secured tothe portion a of the casing, as is the case with the single camillustrated in Figs. 1, 2, and 3.

In the modified form of the cams shown in Figs. 10 and 11 the springsworking on the slides are omitted. In this case two pistonslides g and gare arranged one hundred and eighty degrees apart and positively guidedbetween the cams 1' and 1"", arranged at both ends of the chamber a. Thecurved part of the cam I is opposite and equal to the curved part of thecam 1"; but the latter curved part is inwardly (the former is outwardly)directed. The distance between the two cams is in all small parts equalto the length of the pistonslides, which are adapted to advance at bothfront sides of the rotating head 7. In order to avoid a too greatpressure of the slides gitudinal perforations 9 are provided in theslides. When a slide enters in the curved part, the entrance to thesechannels 1 becomes free and the fluid passes through the channels fromone side of the slide to the other one. If the slide passes in thedirection of the arrow into the position shown in Fig. 8, the fluidpasses through the channels from the right hand above space in to theleft-hand space Ir at the bottom and equalizes the pressure. During theworking of the slides between the flat parts of the cams the channels gare closed at both ends.

It is obvious that the apparatus may be used either as a motor todeliver power from the shaft 0, the impelling fluid being steam, airunder compression, water, explosive gases, &c., or that power may beapplied to the shaft to induce the movement of any fluid, or, in otherwords, that the machine may be used as a pump. WV hen used as a motor,the motive fluid enters the inlet-opening 0. The slides being in theposition shown in Figs. 1, 2, and 3, the motive fluid exerts itspressure against the slide the rise of the cam constituting a reactionabutment. The head f is threfore rotated in the direction of the arrow,and slide g is gradually exposed to the motive fluid by the decreasingcurvature of the cam. A recess p is provided in the shell or casing a,which permits the same pressure to exist on both sides of the slide 1until it has passed the point 10. A similar recess 12 is also providedin the casing (a and from this recess the fluid is discharged throughthe outlet w. When two cams are employed, as in Fig. 6, the sameoperation takes place on each side of the rotating head. The operationof the apparatus when used as a pump to cause the circulation of anyfluid will be obvious from the foregoing without further description.

It will be noted that it is immaterial whether the head revolves and thecams remain stationary, or vice versa, as only the relative movement ofthese parts is necessary to the operation of the machine. It should alsobe noted that the sizes of the inlet and outlet openings should varywith the density of the motive fluid used. For example, they should belarger for water than for compresed air.

I claim as my invention 1. In a motor the combination with a power oroperating chamber of a cam in one end of said chamber having a curvedrise portion and a flat portion, said curved rise portion ascendinggradually over a portion of the circular surface of the cam to themaximum rise and then falling gradually over a like portion of thesurface, the rise and fall each forming a concavity and beingsymmetrical with respect to the maximum rise, longitudinally-movablepiston-slides guided by the cam and a head for holding said slides, saidcam and head being adapted to have a relative rotary movement.

2. In a motor the combination Witha power or operating chamber of a camin one end of said chamber having a curved rise portion and a flatportion, said curved rise portion ascending gradually over substantiallyone quarter of the circular surface of the cam to the maximunr riseandthen falling gradually over sub' stantially the next quarter of thesurface, the rise and fall each forming a concavity and beingsymmetrical with respect to the maximum rise, two longitudinally-movablepiston-slides one hundred and eighty degrees apart guided by the cam,and ahead for holding said slides, said cam and head being adapted tohave a relative rotary movement.

3. In a motor, the combination with a power or operating chamber, of arotating head,

WILHELM VON PITTLER.

In presence of' RUDOLPH FRIoKE, B. H. WARNER, Jr.

